This invention relates to copying apparatus, and more particularly to a copying apparatus provided with an optical device capable of varying the rate at which an original is enlarged or reduced in producing a copy of the original in document copying.
In copying apparatus used for document copying, the position in which an original from which a copy is to be illuminated by light rays emanating from a light source and the position in which a photosensitive element is exposed to an optical image of the original are fixed, and an optical device for introducing to the photosensitive element the light rays which have illuminated the original has a complex optical path because it uses a lens and a plurality of mirrors for reflecting the light rays several times, in order to obtain a compact overall size in a copying apparatus. The more complex the optical path, the more complex becomes the construction of the device for varying the rate at which the original is enlarged or reduced in producing a copy or copy size varying device.